It has become common practice to pass generally, spherical structures, known in the art as pigs, through oil and gas pipelines to perform various functions, such as to establish the interface between separate substances being conveyed through the pipeline, to clean the pipeline, and to measure the flow or other properties in the pipeline. To launch the pigs into the pipeline, various structures have been employed. One of these is shown in Eagleton U.S. Pat. No. 3,169,263 wherein an inclined barrel having a supply of spherical pigs is connected to the pipeline so that an escapement can direct pigs into the pipeline. Pigs are loaded into the barrel which usually has an internal diameter greater than the diameter of the pipeline and the pigs. The pigs move by gravity from the barrel into the pipeline. To control the movement of the pigs into the pipeline, escapement arrangements are employed. The most common is illustrated in Osborne U.S. Pat. No. 2,955,157 wherein two reciprocated pistons control the innermost two pigs in a barrel. To launch a pig, the lowermost pig is released by retracting the forward piston. The rear piston prevents the second pig from being launched at that time. Thereafter, the position of the two pistons is reversed so that a new pig is placed into the lower, launch position. Valves isolate the barrel from the pipeline when a new supply of pigs is loaded into the barrel. These prior launchers were generally not used as pig receivers to remove the pig from the pipeline at some remote location. Thus, special barrel receivers were needed. To provide reversibility for the launcher, so that it could be used as a receiver, a mechanical device as shown in Walker 3,232,090 was suggested. This device is complicated and requires manual actuation for launching pigs. In addition, complicated structure had to be mounted onto the barrels themselves. Because of this complexity, the use of a barrel construction that could be employed both as a launcher and as a receiver for pigs has not been generally available in the field. Consequently, pipelines still employ unidirectional devices, one for launching pigs and the other for receiving pigs. This requires an increased number of barrels and also separate structural arrangements for various pig manipulation devices.